Manufacturers of electronic equipment typically include electronic power converters as components of electronic products and systems.
For example, electronic power converters are widely used for battery charging systems, providing regulated DC voltages for computer circuits, and for providing sources of alternating voltage from a source of regulated DC power for motor control applications.
A switching converter can perform several basic functions, one basic function is to operate as a switching DC--DC converter. In a switching DC--DC converter, the DC input voltage is converted to a DC output voltage having a larger or smaller magnitude, with possibly opposite polarity and with the possibility of providing isolation of the input and output ground references.
High efficiency is essential in any power processing application. Low power conversion efficiency results in low component reliability because the components dissipate excessive power. High efficiency is also necessary in applications where limited input power is available.
Power conversion losses in a switching type DC to DC converter are a function of several parameters. Switching type DC to DC converters use switching elements in the process of power conversion. These switching elements dissipate power in the conversion process. Obviously, decreasing the number of required switching elements can reduce the switching losses.
The mass of a switching type DC to DC converter is also related to switching frequency. This is due to the direct relationship between the size of the magnetic components used within the converter and the switching frequency. Higher switching frequency results in a smaller size required for the magnetic components used in the converter. Higher switching frequency can result in a converter with lower mass because the magnetic components can be smaller. Unfortunately, higher switching frequencies result in higher switching losses in the switching elements within switching DC--DC converters. If the number of switches in a converter can be minimized, switching losses can be minimized, and the switching frequency can be increased to achieve a converter with both lower mass and high efficiency.
There is a need for switching DC--DC converter topologies that can minimize the number of switches required and also process power in such a way that high efficiency and low mass can be achieved simultaneously.